Costa Rica discovers new crab species

December 3, 2010

A group of Costa Rican biologists has discovered a new species of river crab, and experts believe the crab exists only in the country’s Southern Zone.

The discovery of Allacanthos yawi was published in the September 2010 edition of the zoological taxonomist journal Zootaxa.

The new species was found at 1,000 meters above sea level, along the banks of the Río Volcán and in the Río Grande de Térraba basin. The crabs were also found along the Cañas River.

The male crab measures 2.8 centimeters in width and 1.6 cm in length, and the female can grow to 2.7 cm wide.

They are distinguished by olive and green colors on their backsides, and yellow and turquoise shades on their bellies.

Costa Rica has 18 species of river crabs representing six different genera, including the most recent discovery.

For Ingo Wehrtmann, a University of Costa Rica Zoology Museum researcher who helped identify the crustacean, the discovery is a rare treat.

“To discover a new species of river crab for the country isn’t something that happens often,” he said.

The crab was originally found in 2009 by Luis Rólier Lara, a biologist working near the Southern Zone’s Buenos Aires. Lara was conducting research for the Costa Rican Electricity Institute’s proposed El Diquís hydroelectric plant.

The dam, should it be built, would be the largest hydroelectric project in Central America, producing up to 630 megawatts.

After discovering the crab, Wehrtmann pushed for its protection, warning that expansion of nearby pineapple farms could threaten the crab’s habitat.

“This discovery should motivate us to protect the rivers, streams and habitats that shelter a large number of aquatic insect species, fish and now crabs that are unique to Costa Rica and are being threatened by pollution,” he said.

Brazilian crab expert Célio Magalhaes described the new species for Zootaxa, and its name was chosen with help from Costa Rican archaeologist Melania Pérez.

Yawi means “river crab that lives under rocks” in Cabécar, an indigenous language from the region.

Scientists based the identification of the new species on the male’s gonopod, or external reproductive appendage.

According to the paper published in Zootaxa, the Allacanthos yawi male is the first known river crab with a gonopod that has a “narrowing distal part.” By comparison, other types of Allaconthos river crab have straight gonopods.

Research on and identification of Allacanthos yawi was funded by Brazil’s National Board of Scientific and Technological Development and by Costa Rica’s National  Board of Scientific and Technological Research.

You may be interested

Our High Season Print Edition is here! Here’s where to find it
The Tico Times
333 views
The Tico Times
333 views

Our High Season Print Edition is here! Here’s where to find it

Katherine Stanley - December 11, 2017

In the weeks since the relaunch of The Tico Times on Sept. 1, we’ve been hard at work to reconnect…

Bright Lights Boat Parade inaugurates holiday season in Quepos
Events
410 views
Events
410 views

Bright Lights Boat Parade inaugurates holiday season in Quepos

Elizabeth Lang - December 11, 2017

The Bright Lights Boat Parade marked the official kickoff of the holiday season in the Central Pacific town of Quepos…

Strong winds cause three deaths in Costa Rica, one in El Salvador
Weather
2872 views
Weather
2872 views

Strong winds cause three deaths in Costa Rica, one in El Salvador

AFP - December 10, 2017

Three people have died in Costa Rica, includiing two Swiss tourists, and one in El Salvador as a result of…